Important Questions for Class 11 Biology- Structural Organisation in Animals

Animals are made up of different types of cells. Different organisms have different structural organizations. The different cells combine to form tissues. A number of tissues together form an organ, and different organs collectively form an organ system. The different types of tissues include- epithelial tissue, connective tissue, skeletal tissue, muscular tissue, and neural tissue.


Q.1. Which sugar is present in milk? How many monosaccharide units does it contain?
A.1. Lactose, a disaccharide sugar is present in milk. It consists of two monosaccharide units- D-glucose and D-galactose.

Q.2. Which linkage connects the monosaccharide unit in a polysaccharide?
A.2. ꞵ- 1,4’-glycosidic linkage

Q.3. Name an invert sugar. Why is it called so?
A.3. Sucrose is an example of invert sugar. It is called an invert sugar because the hydrolysis inverts the rotation of plane-polarized light.

Q.4. What are the conditions when glucose is converted into gluconic and saccharic acid?
A.4. When glucose is oxidized with mild oxidizing agents such as bromine and water, it is converted into gluconic acid. When oxidized with strong oxidizing agents such as HNO3, glucose is converted into saccharic acid.

Q.5. Match the following:

Column I Column II
Compound epithelium Alimentary canal
Compound eyes Cockroach
Septal nephridia Skin
Open circulatory system Mosaic vision
Typhlosole Earthworm

A.5. Compound epithelium- Skin Compound eyes- Mosaic vision Septal nephridia- Earthworm Open circulatory system- Cockroach Typhlosole- Alimentary canal

Q.6. Mention the cellular components of blood.
A.6. Blood contains the following components:

  • Plasma
  • Red Blood Cells
  • White Blood Cells
  • Platelets

Q.7. State the functions and types of nephridia in an earthworm.
A.7. Functions:

  • It regulates the composition and volume of body fluids.
  • It starts as a funnel that collects excess fluid from the coelomic chamber.
  • This organ connects to the tubular parts of nephridium and the waste is delivered to the surface through a pore.

Types of Nephridia:

  • Septal nephridia
  • Pharyngeal nephridia
  • Integumentary nephridia

Q.8. Mention the functions of each of the following:

  1. Ureters in frog
  2. Malpighian tubules
  3. Body wall in the earthworm


  1. Ureters in frog– Ureters carry sperms and excretory waste to the cloaca. They also carry the ova.
  2. Malpighian tubules- Each tubule is lined by glandular cells and carries out excretion. The glandular cells absorb the excretory materials which are then converted into uric acid. It is then released out through the hindgut.
  3. Body wall in Earthworm– The body wall comprises basal cells, receptor cells and gland cells. The body wall provides support and the cells secrete mucus to keep the skin moist. The muscles provide strength and rigidity.

Q.9. Give a brief account of the circulatory system of earthworm.
A.9. The earthworm has a closed circulatory system. It consists of capillaries, blood vessels and heart. The blood is confined to the heart and blood vessels due to the closed system. The smaller blood vessels supply the gut, body wall and nerve cord. The 4th, 5th, and 6th segments comprise blood, glands that produce blood cells and haemoglobin which dissolves in the plasma.

Q.10. Where are the following found in the animal body?

  1. Chondrocytes
  2. Axons
  3. Ciliated epithelium


  1. Chondrocytes- These cells are found in the cartilage of the connective tissue and secrete matrix.
  2. Axons- It is a long fibre with a long distal end. There is a bulb-like structure called synaptic knob at the end. Axons transmit nerve impulse away from the cells.
  3. Ciliated epithelium- They help in the movement of particles or fluid over the epithelial surface in structures such as the trachea, nasal cavities, bronchial tubes.

Q.11. What are the different cell junctions found in tissues?
A.11. The following cell junctions are found in tissues:

  • Tight Junctions- The plasma membrane of adjacent epithelial cells are held close to each other.
  • Gap Junctions- They facilitate the exchange of chemicals between adjacent cells.
  • Adhering Junctions- They help in connecting the neighbouring cells together.

Q.12. How are frogs beneficial for mankind?
A.12. Frogs feed on insects and protect the crops. They are an important link in the food chains and the food web in the ecosystem. Their legs are also a source of food.

Q.13. Where are the hepatic caecum in a cockroach located? What is its function?
A.13. The hepatic caecum is present at the junction of foregut and midget. It secretes digestive juices and helps in the digestion process.

Q.14. Give two identifying features of an adult male frog.
A.14. Following are the features of an adult frog:

  • The loose skin folds in the throat of a male frog known as vocal sacs. They produce a croaking sound.
  • Nuptial pads are copulatory pads present on the forelimb of the male frog. These help in closing the female during Amplexus.

Q.15. Answer in one line:

  1. Where are the ovaries in a cockroach located?
  2. How many spermathecae are present in an earthworm?
  3. How many segments does the abdomen of the cockroach contain?


  1. 4th, 5th, and 6th abdominal segments
  2. Four pairs of spermathecae in the 4th, 5th, and 6th abdominal segments.
  3. 3-7 segments.

Q.16. What is connective tissue?

A.16. The group of tissues composed of an extracellular matrix is collectively called the connective tissues. Blood, bones, tendon, adipose, ligaments and areolar tissues are examples of connective tissues. There are three different types of connective tissue:

  1. Fluid Connective Tissue.
  2. Fibrous Connective Tissue.
  3. Skeletal Connective Tissue.

Q.17. Which organ is present both in male and female cockroaches?

A.17. Anal cerci, an essential sense organ is present in both male and female cockroaches. They are a pair of appendages present at the end of the abdomen and functions by detecting vibrations and are wind sensitive.

Q.18. What is adipose tissue?

A.18. Adipose tissue is also called as the fat tissue. They are connective tissue composed of adipocytes and are primarily located beneath the skin. Its main function is to insulate the body and stores energy in the form of fat.

Q.19. Name the process by which a tadpole develops into an adult frog?

A.19. The process in which a tadpole turns into a frog is called metamorphosis.

Q.20. What is the difference between cutaneous and pulmonary respiration?

A.20. Cutaneous respiration refers to the exchange of gases, which occurs through the form the skin while pulmonary respiration refers to the exchange of gases through the lungs.

Q.21. What is the common name of Periplaneta Americana?

A.21. The common name of Periplaneta Americana is the American cockroach

Q.22. List out the cellular components of blood?

A.22. The cellular components found in blood are collectively called as blood corpuscles. The three types of blood corpuscles are:

  1. Red blood corpuscles- RBC’s
  2. White blood corpuscles-WBC’s
  3. Blood Platelets

Q.23. Mention the function of Ureters in frog?

A.23. Frogs are amphibians with two ureters that emerge from the kidneys.

In males, the ureters function as a urogenital duct that opens into the cloaca. It helps in passing the urine as well as the sperm to the exterior. In females, the ureters open separately in the cloaca and excrete only the urine.

Q.24. What are osteoclast and osteoblast?

A.24. The osteoclast is the bone cells responsible for the dissolving of bones by removing the mineral matrix and the collagen part of the bone. The osteoclast is the bone cells responsible for bone formation.

Q.24. What are Tissues? What are the 4 major types of tissues?

A.24. Tissues are an integrated group of cells which performs similar functions and possess a similar cellular structure. These tissues provide a basic framework in multicellular animals. There are four different types of tissues:

  1. Epithelial tissue
  2. Connective tissue
  3. Muscular tissue
  4. Nervous tissue

Q.25. What is the structural Organization of an animal?

The structural organization of a typical multicellular animal is as follows:

                 Cells   → Tissues   → Organs → Organ system

Q.26.  What are the functions of Muscular and Nervous tissue?

Muscular tissues are involved in the Locomotion and movement, whereas Nervous tissue plays an essential role in control and coordination.

Q.27. Define organs and the organ system.

A collection of tissue forms an organ and a group of organs that work together to perform one or more functions is called an organ system.

Q.28. What are the Epithelial Tissues?

Epithelial Tissues are membranous bound tissues, which are composed of one or more layers of cells. These tissues play an important role in forming the covering of most internal and external surfaces of the body.

Q.29. Which tissue provides support and surface for attachment of muscle?

Skeletal connective Tissues. This tissue forms a frame network of the body and provides protection and rigidity to the various organs of the body.

Q.30. How many types of neurons are there?

Based on the functionality of the neurons, they are classified into three types:

  1. Sensory neurons or afferent neurons.
  2. Motor neurons or efferent neurons. 
  3. Interneurons.

Based on the structure, neurons are again classified into two types

  1. Bipolar neurons 
  2. Multipolar neurons 

For more information on Structural Organization of Animals or any Biology article, keep visiting BYJU’S website or download BYJU’S app for further reference.

Also, Access Class 11 Biology Sample papers 

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1 Comment

  1. thankyou for the questions
    it was very useful : )

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